Chemical ionization mass spectrometry of steroids and other lipids

Lin, Yong Y.; Smith, Leland L.

doi:10.1002/mas.1280030302

Cited by 28 publications

(7 citation statements)

References 194 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In addition, chemical ionization with methane as reagent gas was also tested and no considerable improvements were observed (results not presented here). Reagent gases other than methane, particularly NH 3 , may be of interest to investigate in this respect (29). The sterol oxides were quantitated by capillary column GC by comparing the relative retention times with those of the authentic samples in this study.…”

Section: Resultsmentioning

confidence: 99%

Studies on phytosterol oxides. I: Effect of storage on the content in potato chips prepared in different vegetable oils

Dutta

Appelqvist

1997

J Americ Oil Chem Soc

View full text Add to dashboard Cite

Potato chips fried in palm oil, sunflower oil, and high-oleic sunflower oil were studied for the content of different phytosterol oxides during 0 to 25 weeks of storage in the dark. Oxidation products of sitosterol (24α-ethyl-5-cholesten-3β-ol) and campesterol (24α-methyl-5-cholesten-3β-ol) were synthesized to help identify the phytosterol oxides. The oxides of phytosterols were analyzed by preparative thin-layer chromatography, solid-phase extraction, capillary column gas chromatography (GC), and GC-mass spectrometry. Epimers of 7-hydroxysitosterol and 7-hydroxycampesterol; 7-ketositosterol and 7-ketocampesterol; epimers of 5,6-epoxy-sitosterol and 5,6-epoxy-campesterol; 24α-ethylcholestane-3β,5,6β-triol (dihydroxysitosterol) and 24α-methylcholestane-3β,5,6β-triol (dihydroxycampesterol) were detected and quantitated in the samples of chips fried in different vegetable oils. Potato chips fried in palm oil had the lowest level of total sterol oxides, ranging from 5 to ca. 9 ppm in the lipids from time 0 to 25 wk of storage. The level of total sterol oxides in chip samples fried in sunflower oil ranged from 46 to 47 ppm, and the lipids in samples fried in high-oleic sunflower oil ranged from 35 to 58 ppm from 0 time to 25 wk of storage. During 25 wk of storage no considerable increase in sterol oxides was observed in the samples of chips fried in palm oil and sunflower oil. The chip samples fried in high-oleic sunflower oil had slightly higher levels of sterol oxides after 10 and 25 weeks of storage. In addition to the levels of individual sterol oxides, a new method for enrichment of phytosterol oxides from the unsaponifiables and full-scan mass spectra of various oxidation products of sitosterol and campesterol are reported in this paper. JAOCS 74, 647-657 (1997).

show abstract

Section: Resultsmentioning

confidence: 99%

Studies on phytosterol oxides. I: Effect of storage on the content in potato chips prepared in different vegetable oils

Dutta

Appelqvist

1997

J Americ Oil Chem Soc

View full text Add to dashboard Cite

show abstract

“…Detailed information can be obtained in numerous books and reviews (Zaretskii, 1976;Brooks and Gaskell, 1980;Budzikiewicz, 1980;Elliott, 1980;Gerst et al, 1997;Griffiths et al, 2005). Chemical ionisation of steroids has been also been reviewed (Lin and Smith, 1984). The four most general types of fragmentation are: loss of a methyl group (angular or from a TMS group), loss of hydroxyl groups as water (or its equivalent in derivatives), loss of the side-chain, and loss of part of or the entire D-ring.…”

Section: General Patterns Of Ei Fragmentation Of Derivatised Steroidsmentioning

confidence: 99%

Spectroscopic Methods of Steroid Analysis

Kasal¹,

Budêšínský²,

Griffiths³

2010

Steroid Analysis

View full text Add to dashboard Cite

“…CI mass spectra of sterol hydrocarbons and steroid hormones have been obtained by using CH 4 , i -C 4 H 10 , and NH 3 as the reagent gases [28]. The gases CH 4 and i -C 4 H 10 mainly produce M+H + and dehydrated fragment ions (M+H + -nH 2 O).…”

Section: Introductionmentioning

confidence: 99%

“…When using NH 3 as the reagent gas, M+NH 4 + , M+H + and dehydrated fragment ions (M+H + -nH 2 O) are commonly formed. Although some nonpolar lipids (such as 5α-cholestane) and polar lipids (steroid hormones) can be analyzed by using these methods [28], the issue of forming many ions from one analyte is a problem for mixture analysis.…”

Section: Introductionmentioning

confidence: 99%

Characterization of nonpolar lipids and selected steroids by using laser-induced acoustic desorption/chemical ionization, atmospheric pressure chemical ionization, and electrospray ionization mass spectrometry

Jin

Daiya

Kenttämaa

2011

International Journal of Mass Spectrometry

View full text Add to dashboard Cite

Laser-induced acoustic desorption (LIAD) combined with ClMn(H 2 O) + chemical ionization (CI) was tested for the analysis of nonpolar lipids and selected steroids in a Fourier-transform ion cyclotron resonance mass spectrometer (FT-ICR). The nonpolar lipids studied, cholesterol, 5α-cholestane, cholesta-3,5-diene, squalene, and β-carotene, were found to solely form the desired water replacement product (adduct-H 2 O) with the ClMn(H 2 O) + ions. The steroids, androsterone, dehydroepiandrosterone (DHEA), estrone, estradiol, and estriol, also form abundant adduct-H 2 O ions, but less abundant adduct-2H 2 O ions were also observed. Neither (+)APCI nor (+)ESI can ionize the saturated hydrocarbon lipid, cholestane. APCI successfully ionizes the unsaturated hydrocarbon lipids to form exclusively the intact protonated analytes. However, it causes extensive fragmentation for cholesterol and the steroids. The worst case is cholesterol that does not produce any stable protonated molecules. On the other hand, ESI cannot ionize any of the hydrocarbon analytes, saturated or unsaturated. However, ESI can be used to protonate the oxygen-containing analytes with substantially less fragmentation than for APCI in all cases except for cholesterol and estrone. In conclusion, LIAD/ClMn(H 2 O) + chemical ionization is superior over APCI and ESI for the mass spectrometric characterization of underivatized nonpolar lipids and steroids.

show abstract

Chemical ionization mass spectrometry of steroids and other lipids

Cited by 28 publications

References 194 publications

Studies on phytosterol oxides. I: Effect of storage on the content in potato chips prepared in different vegetable oils

Studies on phytosterol oxides. I: Effect of storage on the content in potato chips prepared in different vegetable oils

Spectroscopic Methods of Steroid Analysis

Characterization of nonpolar lipids and selected steroids by using laser-induced acoustic desorption/chemical ionization, atmospheric pressure chemical ionization, and electrospray ionization mass spectrometry

Contact Info

Product

Resources

About